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LABORATORY DIAGNOSIS OF PARASITIC INFECTIONS. Case diagnosis. History (Age, occupation, residency, previous infection) Complaint Clinical examination Invesigations - Laboratory investigations - Radiology - Surgical intervention (Exploratory). Provisional diagnosis.
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Case diagnosis • History (Age, occupation, residency, previous infection) • Complaint • Clinical examination • Invesigations - Laboratory investigations - Radiology - Surgical intervention (Exploratory) Provisional diagnosis Confirm the diagnosis
Ether Dissolve fat M.f Acetic acid RBC haemolysis Clear ova
SEDIMENTATION CONCENTRATION URINE EXAMINATION Clean conical glass receptacle 15-20 min Centrifuge (2 min)
URINE EXAMINATIONMembrane filtration technique air 10 ml urine Nucleopore filter + Saline Eggs of Schistosoma
Saline smear Iodine smear STOOL EXAMINATIONTemporary saline Iodine 1% • Huge number of: • Eggs • Protozoal troph. Motility • (Amoeb, flagellates) • Huge number of: • Cyst morphological details
STOOL EXAMINATIONScanty infectionConcentration techniques Sedimentation Floatation • Non Operculated eggs • Trematodes ( S. m.) • Cestode • Nematode(Hookworms,Trichostong) • Cysts • Heavy eggs (Ascaris egg) • Operculated eggs (Trematodes) • Larvae (Strong sterc.) • Cysts
STOOL EXAMINATIONSaline sedimentation Mesh wire gauze Saline Emulsify Conical flask 10 g stool Sediment
STOOL EXAMINATION Formol Ether Sed. Conc. Ether Ether debris 10% Formalin formalin 1 g stool Sediment Thorough mixing Conical flask centrif. tube • Ether adsorbs fecal debris & floats. • Formalin fixes & preserves the specimen.
STOOL EXAMINATION Clean light eggs & cysts Tin container Seive 20 min Centrif. 2 min
STOOL EXAMINATIONPermanent Stained smears • Iron haematoxylin stain • Trichrome stain • Modified Ziehl Neelsen stain (Crypto.)
STOOL EXAMINATION Kato technique Mesh screen Hole Template Remove the template Cellophane soaked by glycerin (clears faeces( Egg count/ g stool Egg quant. Of: Ascaris, T. trich., Hookworms, S. mansoni
STOOL EXAMINATION Stoll’s technique Egg quant. Of: Ascaris, T. trich., Hookworms, S. mansoni 24 hr stool 60 CC 4 g Stool 56 CC NaOH Shake well 0.15 CC Egg count/ slide Eggs/1g= Eggs/slideX100 Erlynmeyer flask Egg/day=Eggs/1g X stool wt/g in 24 hrs
STOOL EXAMINATION Baermann’s technique Stool/soil seive 25-50CC Warmwater Glass funnel 30 min • centrifuge clamp Detec. Of Nematode L. /stool, soil
Filter paper culture STOOL EXAMINATION Cultures for Nematode larvae Filter paper Slide Sealed petri dish Water • Scanty infection • Larvae of: • St. stercoralis (A,L) • Hookworms • Trichostrong
NaOH Sputum Centfifuge
floor Edge
Thin Thick BLOOD EXAMINATIONBLOOD FILMS Bld drop Circular motion spread Air dry Air dry methyl alcohol Geimsa Geimsa Malaria, Babesia, Filaria, Tryp.
BLOOD EXAMINATIONBuffy coat film plasma WBC (BC) centrifuge Air dry Fix 30 min RBC spread Geimsa Citrated bld Tryp., L. donovani
BLOOD EXAMINATIONQBC technique RBC +parasite Acridine orange centrifuge RBC Microhaematocrit tube Malaria, Filaria, Trypanosomes
BLOOD EXAMINATIONKNOTT’S CONC. TECHNIQUE • Citrated bld 1 ml 10 ml centrifuge Geimsa Air dry fix 2 min sediment Formalin 2 % Filaria
INDIRECT IMMUNOLOGICAL METHODS • Scanty infection. • Tissue parasite no portal of exit (Hydatid dis.) • Migratory stage (Fasciola) • Chronic infection fibrosis (Bilharziasis)
IHAT LAT INDIRECT IMMUNOLOGICAL METHODS Ag Ag + + Patient’s serum (?? AB) Latex particle Patient’s serum (?? AB) Sensitized Sheep’s RBC (O–ve) Agglutination Agglutination
INDIRECT IMMUNOLOGICAL METHODSINDIRECT FLUORESCENT ANTIBODY TEST fluorescein Anti human AB Patient’s serum (?? AB) parasite
INDIRECT IMMUNOLOGICAL METHODSELISA OPD Peroxidase E OPD Anti human AB Patient’s serum (?? AB) AB Ag Flat bottom plastic micrititre plate
INDIRECT IMMUNOLOGICAL METHODSCFT Sheep’s RBC Anti sheep AB +ve Ab No Sheep RBChaemolysis AB complement Patient’s serum (?? AB) -ve Ab haemolysis Ag Tube / microplate
INDIRECT IMMUNOLOGICAL METHODSDouble Electro Immuno Diffusion Line of ppt Electric current +ve Ab Ag -ve Buffered gel
INDIRECT IMMUNOLOGICAL METHODSImmunodiagnostic Strip Test (Dip Stick Test) Ag +ve -ve Pt bld (?Ag) Coloured dye Monoclonal Ab Nitrocellulose strip Malaria, Filaria, African tryp.
MOLECULAR BIOLOGICAL TECHNIQUESDNA Probes Radio active material Commercially prepared DNA sequence DNA Probe Hybridization +ve parasite Nitrocellulose paper Sample (Serum/ stool) ?? parasite Radioactivity
MOLECULAR BIOLOGICAL TECHNIQUES Polymerase Chain Reaction (PCR) Single stranded DNA Replication Detection T cruzi, T gondii